Javascript:如何延迟为img.complete返回值 [英] Javascript: How can I delay returning a value for img.complete

问题描述

我已经编写了一个脚本来测试IMG标签中对SVG的支持:

I've written a script to test for SVG support in the IMG tag:

function SVGinIMG() {
  var SVGdata = 'data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSIyNzUiIGhlaWdodD0iMjc1Ij48L3N2Zz4%3D'
  var i = document.createElement('img');
  i.setAttribute('src',SVGdata);
  return i.complete;
}
window.onload = function() {
  var hasSVG = SVGinIMG();
  alert(hasSVG);
}

这就是我想要的，除了在WebKit浏览器中运行脚本时， complete 属性不会在我第一次加载页面时触发；而是在第一次加载页面时触发.当我刷新页面时，它可以正常工作. return 函数在img完成加载之前正在运行；延迟此操作的最佳方法是什么?

This does what I want, except that when I run the script in WebKit browsers the complete property doesn't trigger the first time I load the page; when I refresh the page, it works as it should. The return function is running before the img has finished loading; what's the best method to delay this?

推荐答案

我有点使事情复杂化了.我真正需要的只是 load 事件:

I was complicating things a little; all I really needed was the load event:

function SVGDetect() {
  var testImg = 'data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSIyNzUiIGhlaWdodD0iMjc1Ij48L3N2Zz4%3D';
  var img = document.createElement('img')
  img.setAttribute('src',testImg);
  img.addEventListener('load',setCSS,true);
}

此功能会在加载图片时运行另一种功能，而对于不支持图片中SVG的浏览器则不会.

This runs another function when the image loads, which is never in the case of browsers that don't support SVG in images.

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